I get an error "recording failed with error: failed to encode the video frame " when trying export UltraHD Video with MP4 container with h.264 codecWindows 8.1Resolve 14b6 (but with 12.5 same error) free versionif I choose Quicktime with MPEG 4 it worksAs primary 4k export to youtube so they recommend MP4/h.264Why I get error and what to do?

Surprisingly, You Tube accepts DNxHD for HD uploads. (Though frustratingly, not when exported from DaVinci Resolve. It does work when exported from Adobe Premiere Pro. So BMD...something's not quite right with your DNxHD exports.)

I was told that YouTube now also accepts DNxHR, which is needed for higher than HD resolutions, so maybe try that.

Jim Simon wrote:Surprisingly, You Tube accepts DNxHD for HD uploads. (Though frustratingly, not when exported from DaVinci Resolve. It does work when exported from Adobe Premiere Pro. So BMD...something's not quite right with your DNxHD exports.)I was told that YouTube now also accepts DNxHR, which is needed for higher than HD resolutions, so maybe try that.

that's not very surprising. youtube is just using ffmepg based solutions for transcoding, like most other internet video services.if you can play your file by ffplay, mpv etc., your chances are very good, that it will work on youtube as well.it's also a quite useful way to test and avoid color deviations in advance.